Mine roof supports

ABSTRACT

A mine roof support has a leg alignment device in the form of a resilient steady which extends from a baseplate and is connected at its upper end with the leg through a variable length device. The variable length device is an eccentric in the form of a pin on a plate rotatable and lockable on the top of the steady. The pin is connected by a connecting rod to the leg.

United States Patent inventor Appl. No.

Filed Patented Assignee Priority Hans-Wilm Heimburg Recklinghausen, Germany 819,781

Apr. 28, 1969 Dec. 7, 1971 Gullick Limited Lancashire, England Oct. 2, 1968 Germany MINE ROOF SUPPORTS 5 Claims, 2 Drawing Figs.

US. Cl

Int. Cl

Field of Search 248/354, 354 C, 354 H, 354 S; 61/45.1, 45.2; 52/1 16 References Cited UNITED STATES PATENTS 1,553,800 9/1925 Brandt 2,908,461 10/1959 Coffeen 3,309,054 3/1967 Davis-Ratcliife. 3,437,010 4/1969 Jacobi et a1 Primary Examiner-William H. Schultz Almmeylmirie & Smiley ABSTRACT: A mine roof support has a leg alignment device in the form of a resilient steady which extends from a baseplate and is connected at its upper end with the leg through a variable length device. The variable length device is an eccentric in the form of a pin on a plate rotatable and lockable on the top of the steady. The pin is connected by a connecting rod to the leg.

PATENTED nu: Han SHE 1 BF 2 3625465 INVENTORZ HANS-WM. M em sum PATENTED [1E8 H911 SHEET 2 OF 2 INVENTOR: HE! N BURG- HANS-WILM MINE ROOF SUPPORTS The invention concerns a mine roof support having a resilient steady or stay for a leg of the support, the leg being freely and universally pivotal on a baseplate.

The leg is freely and universally articulated to the baseplate to allow the mine roof support to yield to earth forces which would otherwise destroy the support. However, the leg must be held upright in its freestanding angular orientation while it is being set and it is known to provide some fonn of resilient steady.

In some cases, it is preferred that the leg have a forwardly inclined freestanding angular orientation to take account of expected working conditions which will offset the leg rearwardly. The steady has to prevent the leg toppling over due to its own weight and the weight of the canopy.

According to one aspect of the present invention there is provided a mine roof support having a baseplate and a mine roof support canopy mounted therefrom by an extensible leg universally articulated to the baseplate and the canopy at its end, in which a resilient steady for the leg extends from the baseplate and is coupled at its upper end with the leg to control its freestanding angular orientation through a variable length device.

According to another aspect of the present invention there is provided a mine roof support having a baseplate and a mine roof support canopy mounted therefrom by an extensible leg universally articulated to the baseplate and the canopy at its ends, in which a resilient steady for the leg extends from the baseplate and is coupled at its upper end with the leg to control its freestanding angular orientation by an arrangement in which two members can be locked in selected angular orientations to provide a coupling between said upper end and the leg of adjustable length.

The variable length device comprises suitably two horizontally disposed discs one above the other, the lower one of which is tightly connected with the upper section of the leg support, while the upper disc can rotate on the bottom disc and can be locked in position. The upper disc has an eccentrically arranged upwardly pointing spigot. The leg is connected with the spigot via a connecting device.

By turning and fixing the upper disc relative to the bottom disc it is possible to alter the angular disposition of the leg continuously in any direction. Thus the support can be adapted simply to any working conditions, without structural alterations.

For the connection between the spigot of the eccentric device and the leg a connecting rod is suitably provided which has an eye on the side facing the resilient steady and into which the spigot is inserted and which has a collar on the side facing the leg. The collar embraces the leg. This kind of connection between leg and leg support guarantees that the restoring forces of the steady are transferred to the leg without difiiculty.

Furthermore the upper disc and the bottom disc of the eccentric device are connected with each other by a screw at the common axis of the discs and can be locked against each other. After releasing the screw the upper disc can thus be turned relative to the lower disc and be locked in any position by tightening the screw.

in a preferred version the lower surface of the upper disc and the upper surface of the lower disc are provided with a number of radial grooves and ridges. This gives better force transmission between the lower and the upper disc because of the increased contact grip. With a suitable large number of radical grooves and ridges the continuous adjustability between leg support and leg is hardly influenced.

Furthermore, all the connections between steady and the leg are suitably held together against vertical forces tending to pull the leg away from the baseplate in the event of the roof bar being caught on the roof during the retraction of the leg.

An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings mine roof sup ort, and 1G. 2 is a p an view.

A foot of a leg 4 rests in a concave surface 3 of a retaining cup 2 on a baseplate 1. A steady 5 in the form of a round springy rod extends from the baseplate at a short distance from the leg and is rigidly attached to the baseplate by means of screws 6. On the top of the steady 5 a lower disc 7 of the eccentric device is fixed. For this purpose the lower disc 7 includes a supporting casing which is open at the bottom and is mounted over the upper end of the steady 5 and fixed by means of a cotter pin 9. Above the lower disc 7 an upper disc 8 is ar ranged. On the surfaces facing each other the lower disc 7 and the upper disc 8 are provided with radial grooves 10 and ridges 11, which mesh with each other at different angle positions of the two discs. The disc 7 is connected with the disc 8 by a screw bolt 12 at the common axis of both discs. This screw bolt 12 can either be inserted through the upper disc 8 from the top, and engage in a thread in the lower disc 7, or it can be inserted through the lower disc 7, from the bottom, and engage a thread'in the upper disc 8. In the case of the arrangement shown in FIG. 1 the head of the screw bolt is sunk suitably into the upper surface of disc 8.

At the upper surface of the upper disc 8 a spigot or stub shaft 13 is eccentrically fixed. The leg 4 is connected with this spigot by a connecting device including a rod 14 which has an eye or collar 15 on the end nearest the steady and which surrounds the spigot or stub shaft 13, a collar 16 at the other end of the rod 14 being made in two parts fastened together by means of bolts 17 to embrace the leg 4.

When the freestanding angular orientation of the leg is to be altered, the screw bolt 12 is released and the upper disc 8 is twisted relative to the lower disc 7. At that moment the eccentrically arranged spigot 13 moves on a circular path around the axis of the steady 5. When the desired position of the leg is reached, the screw bolt 12 is tightened again so that the leg is fixed in this position.

All the connections between steady and leg are arranged, so that the leg cannot be moved out of its position in the base.

1 claim:

1. A support comprising a baseplate,

a prop leg universally articulated on said baseplate and extending upwardly therefrom,

a steady fixed on said baseplate and extending upwardly therefrom in spaced relation to said prop leg,

a brace secured to said prop leg and extending to the upper end of said steady, and

means connecting the upper end of said steady and the free end of said brace, said means comprising two relatively rotatable parts one of which is fixed on said steady and the other of which is connected to said brace and enabling adjustment of said brace relative to said steady to effect angular orientation of said prop leg relative to said baseplate.

2. A support according to claim 1, wherein said brace connected part is rotatably mounted on said steady supported part, and lock means between said parts normally to prevent angular orientation therebetween.

3. A support according to claim 2, wherein said brace connected part includes a shaft parallel to and spaced from the rotational axis of said parts and eccentric thereof, and a collar journaled on said shaft and fixed to the free end of said brace.

4. A support according to claim 3, wherein said lock means comprises interengaging teeth on the abutting surfaces of said parts, and means releasably clamping said parts together to retain said teeth in engagement.

5. A support according to claim 4, wherein said clamping means comprises a bolt extending through one of said parts and threaded into the other of said parts, said bolt being disposed on the rotational axis of said parts. 

1. A support comprising a baseplate, a prop leg universally articulated on said baseplate and extending upwardly therefrom, a steady fixed on said baseplate and extending upwardly therefrom in spaced relation to said prop leg, a brace secured to said prop leg and extending to the upper end of said steady, and means connecting the upper end of said steady and the free end of said brace, said means comprising two relatively rotatable parts one of which is fixed on said steady and the other of which is connected to said brace and enabling adjustment of said brace relative to said steady to effect angular orientation of said prop leg relative to said baseplate.
 2. A support according to claim 1, wherein said brace connected part is rotatAbly mounted on said steady supported part, and lock means between said parts normally to prevent angular orientation therebetween.
 3. A support according to claim 2, wherein said brace connected part includes a shaft parallel to and spaced from the rotational axis of said parts and eccentric thereof, and a collar journalled on said shaft and fixed to the free end of said brace.
 4. A support according to claim 3, wherein said lock means comprises interengaging teeth on the abutting surfaces of said parts, and means releasably clamping said parts together to retain said teeth in engagement.
 5. A support according to claim 4, wherein said clamping means comprises a bolt extending through one of said parts and threaded into the other of said parts, said bolt being disposed on the rotational axis of said parts. 